PC 聚碳酸酯

 

PC 聚碳酸酯

典型应用范围:

电气和商业设备（计算机元件、连接器等），器具（食品加工机、电冰箱抽屉等），交通运输行业
（车辆的前后灯、仪表板等）。

注塑模工艺条件:

干燥处理：PC材料具有吸湿性，加工前的干燥很重要。建议干燥条件为100C到200C，3~4小时。加工
前的湿度必须小于0.02%。
熔化温度：260~340C。
模具温度：70~120C。
注射压力：尽可能地使用高注射压力。
注射速度：对于较小的浇口使用低速注射，对其它类型的浇口使用高速注射。

化学和物理特性:

PC是一种非晶体工程材料，具有特别好的抗冲击强度、热稳定性、光泽度、抑制细菌特性、阻燃特
性以及抗污染性。PC的缺口伊估德冲击强度（otched Izod impact stregth）非常高，并且收缩
率很低，一般为0.1%~0.2%。
PC有很好的机械特性，但流动特性较差，因此这种材料的注塑过程较困难。在选用何种品质的 PC
材料时，要以产品的最终期望为基准。如果塑件要求有较高的抗冲击性，那么就使用低流动率的
PC材料；反之，可以使用高流动率的PC材料，这样可以优化注塑过程。

PC

Generic Class

PC (Polycarbonate)

Typical Applications

Electronic and business equipment (computer parts, connectors, etc.), appliances (food processors, refrigerator drawers, etc.), transportation (head lights, tail lights, instrument panels, etc.).

Injection Molding Processing Conditions

　

Drying

PC resins are hygroscopic and pre-drying is important. Recommended drying conditions are 100 - 120 C (212 - 248 F) for 3 to 4 hours. Moisture content must be less than 0.02% prior to processing. 

Melt Temperature

260 - 340 C (500 - 644 F); higher range for low MFR resins and vice-versa 

Mold Temperature 

70 - 120 C (158 - 248 F); higher range for low MFR resins and vice-versa 

Fill Pressure

As high as possible for rapid molding 

Injection Speed

Slow injection speeds when small or edge gates are used; high speeds for other types of gates 

Chemical and Physical Properties

Polycarbonate is a polyester of carbonic acid. All general-purpose polycarbonates are based on bisphenol A. The bisphenol A component of the molecule contributes to the high glass transition temperature (150 C / 302 F). The rotational mobility of the carbonyl group within the molecule contributes to the high ductility and toughness of the resin.

PC is an amorphous engineering resin with exceptionally good impact strength, heat resistance, clarity, sterilizability, flame retardancy, and stain resistance. The notched Izod impact strength of PC is very high and mold shrinkage is low and consistent (.1 -.2 mm/mm).

High molecular weight PCs (which translate to low melt flow rate) have higher mechanical properties, but processibility of such resins becomes difficult. The type of PC chosen for a particular application should be based on the desired criteria (for high impact properties, use a low-MFR PC; conversely, for optimal processibility, use a high-MFR PC).

The melt viscosities are typically Newtonian up to shear rates of 1000 1/s and decrease beyond that. The Heat Deflection Temperature Under Load is typically between 130 -140 C (266 - 284 F) and the Vicat Softening Point is typically around 155 C (311 F).

Major Manufacturers

Dow Chemical (Caliber), GE Plastics (Lexan), Bayer (Apec, Macrolon), DSM (Xantar), LNP (Lurbricomp, Thermocomp), Mitsubushi Engineering Plastics (Novarex), Teijin Chemical (Panlite).